Sheet in PEEK 1000x620 mm black

Carbon fiber filled PEEK in sheet form gives you one of the stiffest engineering plastics you can mill a part out of. The carbon fiber carries load. It raises stiffness and shape stability far above unreinforced PEEK, while the base material's temperature resistance is kept in full. The sheet handles 260 degrees long term and short peaks around 300 degrees without losing its shape. It is in that range, where other engineering plastics softened long ago, that this grade is still working.

The base is PEEK, a semi-crystalline high temperature plastic with a density around 1.31 g/cm³ and tensile strength in the same neighborhood as several engineering metals. Water uptake is very low, around 0.03 percent. In practice that means parts hold their dimensions even in damp operation and do not swell the way polyamide does, for example. The fire properties are V0, that is, self-extinguishing in the standard test. Chemically the material stands up to most industrial media, from fuels and hydraulic oil to hot water, steam and many acids and bases. The carbon fiber also makes the material electrically conductive, so parts lead static charge away instead of collecting it and discharging uncontrolled. One thing to know: the fiber reinforcement stiffens the material but also makes it more brittle than pure PEEK, so it takes less impact and shock load. Weigh that into the design and you get maximum benefit from the stiffness.

Sheet is the format you pick when the part is to start as a block and get its geometry in the milling machine. Bearing blocks and mounts in measuring equipment where the smallest thermal movement disturbs the reading. Slide plates and guides in process lines that run hot around the clock. Structural components in contact with metal where you want to avoid cold flow under load over time. Design parts in pumps and valves that meet aggressive liquids and where a metal part would have corroded. The low thermal expansion, which the carbon fiber pushes down further, is often the whole point of the choice. The part holds its fit from cold start to full operating temperature.

In machining, carbon fiber filled PEEK behaves more like a free machining metal than like a soft plastic. Use sharp carbide tools, preferably with a ground edge, moderate feeds, and lead the heat away from the cutting zone with coolant or compressed air. The fiber wears on the edge, so count on more frequent tool changes than with unfilled material and plan for it in the calculation. Clamp the blank carefully and avoid point load against thin sections that can otherwise crack. For maximum dimensional stability, thick blanks can be stress relieved before final milling, so that the part does not move once the material has been opened up. Thread with the right tool and at moderate speed, since the hard fibers do not forgive sloppiness.

Worth weighing in is how the material behaves over time and in the cold. PEEK does not shrink and does not crack at low temperatures the way many plastics do, but keeps its toughness far below zero. Creep, meaning the slow deformation under constant load, is low and gets even lower with the carbon fiber counted in. For a bearing block or a mount that has to sit under tension for years, that means the preload does not fall away and that bolted joints keep their grip. The material is also free of moisture from the start, so it needs no conditioning before assembly the way hygroscopic plastics do.

The color of a CF50 part is black, since the carbon fiber colors right through the material. It is not a surface treatment that wears off, it is the material's own shade all the way through. Keep in mind that the conductive property means the part does not work as an electrical insulator. If you need the opposite, a component that insulates, a glass filled or ceramic filled grade is what to look at instead. For gluing and joining to other materials the surface should be pretreated, since PEEK is chemically inert and does not take glue without help. Mechanical fastening with threads or inserts is often simpler and more reliable for this type of part.

Sheets are supplied in several thicknesses and cut to blanks from your drawing, so you avoid paying for material you would mill away anyway. Not sure whether carbon fiber, glass fiber or a low friction grade suits your part best? Send us the documents and we will help you pick the right PEEK grade based on load, temperature and whether the part is to conduct or insulate.

Black PEEK in 1000 x 620 mm gives full width on a shorter sheet, good when the parts are wide but few.